The present invention is related to a digital camera.
Generally, in photographing operations by silver salt film cameras using monochromatic films, such color filters as a green filter, a yellow filter, an orange filter, and a red filter have been employed. When a color filter is employed, such a black/white image is photographed in which a correlation between a light amount of light having a wavelength which penetrates the color filter and a light amount of light entered to this color filter becomes stronger than a correlation between a light amount of light having a wavelength which is absorbed by the color filter and the light amount of the light entered to the color filter. For instance, when a green filter is used, such a light having a wavelength range of a substantially green color is strongly reflected to a contrast of a black/white image, whereas light having other wavelength ranges than the above-explained green-color wavelength range is absorbed by this green filter, and therefore, can be hardly and relatively reflected to the contrast of this black/white image. In photographing operations by silver salt film cameras using monochromatic films, color filters are selectively employed in accordance with sorts of photographing objects. Concretely speaking, for instance, a yellow filter is suitably used to photograph such scenes that a near sight to a middle sight constitute a photographic subject, and an orange filter is suitably used to photograph such a scene as to a far sight, while a telephoto lens is used. A red filter is suitably employed in order to further precisely photograph a far sight. Filters belonging to a green color series can own an effect capable of suppressing red colors, and at the same time, can obtain proper contrasts in a similar effect to that of a yellow filter. As a result, these green-color-series filters can control feelings as to skin and lips of persons to become mellow tones, and are especially suitable for photographing females. In virtue of filter works capable of selectively using these color filters, even when photographing operations are carried out by using monochromatic films in which colors are represented in dark/light monochrome, effects which are fitted to images owned by photographers may be represented.
In the case that black/white images are photographed by using digital cameras, gradation values of pixels every color, which constitute photographed color images, are weighted, and then, the weighted gradation values are added to each other, so that such black/white images can be obtained to which the same effects as those of color filters employed in silver salt film cameras have been given. In other words, the black/white images having strong correlations with a specific color can be acquired. As a consequence, since weighting process for specific color which is wanted to be strongly correlated is selected, filter works similar to those of silver salt film cameras may be realized.
In the case of a silver salt film camera, since a target color filter can be distinguished from other color filters by checking a color of this target color filter, a selection of a desirable color filter can be easily carried out. However, in the case of a digital camera, for example, when such a weighting process is selected by which an equivalent effect to a “yellow filter” of a silver salt film camera may be obtained, and such a weighting process is selected by which an equivalent effect to a “green filter” thereof may be obtained, since physically existing color filters are not selected, disable color filters are selected from a menu displayed on a LCD, or by operating an operation switch. However, in this case, if selection items are displayed by way of character strings such as “yellow filter” and “green filter”, then a user can hardly and intuitively grasp colors. As a result, there is a deterioration problem as to operability of digital cameras.
Further, since a color filter is located in front of a lens in a silver salt film camera, a user can always become aware of presence of this color filter. Accordingly, such an erroneous event can hardly occur. That is, although the user does not want to perform a photographing operation using such a color filter, the user mistakenly performs this photographing operation using the color filter. However, since a color filter is not physically employed in a digital camera, in the case that a user forgets that the color filter has been selected, such an event that a photographed result differs from an expected result may occur.